Machine for grinding and turning brake drums



Jan. 9, 1945.

0. J. E. OLSSON MACHINE FOR GRINDING AND TURNING BRAKE DRUMS 5 Sheets-Sheetl Filed Dec. 26, 1940 INVEVNTORI OLOV J E. OLSSON ATTORNEY Jan; 9; 1945. o. J. E. OLSSON MACHINE FOR GRINDING'AND TURNING BRAKE DRUMS Filed Dec. 26, 1940 s Sheets-Sheet 2 (INVENTOR OLOV 1/. E. 'OLSSO/V ATTO RN F Y Patented Jan. 9, 1945 U T A ES PATENT OFF-ICE a I mmnmanort'diifiirie Ann'runimvd I BRAKE DRUMS 010v J. Olsson, Minneapolis, Minn assignor to Storm Manufacturing Company, Inc., Minneapolis, Minn., acorporation of Minnesota This invention has relation to a lathe, or like machine, designed to be more especially useful to the purposes of grinding and turning brake drums. p I

An object of the invention is to provide a lathe, or grinding and turning-machine, which will be of novel and improved construction.

A further object is to; provide a lathe, or grind ing and turning machine, of the type herein presented wherein will be incorporated variousim proved features and'characteristics of construction novel both as individual entities of said lathe,

intended in no way in a limiting sense, changes in details of construction and arrangement of parts being permissible so long as within the spirit of the invention and the scope of follow. I

In the accompanying drawings forming a part the claims which of j specification,

Fig. l is 'a top plan View ofa machine in which, a

i thefeatures and characteristics of the invention are incorporated Fig. 2-is a side or endelevationa'l view ofthema-f chine of Fig. 1, with the brake drum and apart ofthe support for saidbrake drum removed an'd the grinding tool supporting shaft in s'ectiom] 3 is 'a detail sectional view, taken on line 3%-3in-Fig.2;f y 4 is an enlarged sectional'viewj of theibrake drum support, taken substantially on line 4=4 F Q, L I j Fig. 5 is a; sectional. view detailing gearing or the'machin'e, taken substantially on line 5 -5in Fig. 6 is a detail sectional view, taken l n s-tin Fig.5; c p y I Fig-7 is an enlarged sectionalview, takensub= stantially on" line1 1.in Fig. 2;

Fig. 8 is a detail sectional view, taken ason line 8-8 in Fig. '7; r

Fig. 9Iis an enlarged fragmentary side or end elevational View, artially in section, disclosing parts of the machine in positions other than those 'in=. which' said parts. are' disclosed in Figs. 1 and-2;

Fig.

'10 is an enlarged fragmentary elevational' 1y of the shaft 24 of the electric motor 22.

the disclosure of Fig. 11, butshowing thelatch means in a different position; i

Fig. 13 is a fragmentaryelevational View further detailing said latch means;

Fig. 14 is a detail View disclosing the relation of the cutting tool of the machine to a brake drum when said cutting tool is positioned to perform a turning operation uponsaid brake drum; Fig..'15 is a View corresponding generally with the disclosure of Fig. 4,- but showing a brake drum support of modified construction adapted to be employed inthe machine; and

Fig. 16 is an enlarged fragmentary sectional view detailing features included in the disclosure of Fig. p I I 'With respect to Figs. ;1 to 14 of the drawings and the numerals of reference thereon, a frame for the grinding and turning machine is denoted generally at 20. I Said frame 20 rigidly supports ane'xtension portion 2| of the frame whichin' turn rigidly supports an electric motor 22.

The frame 20 also supports a carriage 23 adapted to be reciprocated uponsaid frame in direction longitudinally thereof and transverse- More explicitly, said carriage 23 includes a base portion 25 thereof slidably movable over an adjacent surface 26 of the frame .20, and oppositely dissaid base portion 25, to provide oppositely disposed guideways 29,29 of the carriage 23 extending longitudinally. of the frame of the machine in 'whic'hopposite side'e'dg e portions 30, 30 of the frame 20 are snugly,:but slidably, situated. The carriage 23 is adapted to be reciprocated longitudi'n'ally of the frame byslidable movement of said carriage and its oppositely disposed guideways 29, 29 along the opposite side edge portions 30', 30 of said frame.

The carriage 23'supports a, bracket member 3| adapted to be adjusted transversely of the frame 20 and perpendicularly to the direction in which,

said carriage is reciprocable along said frame. More explicitly, said bracket member 3| includes a base portion 32 thereof slidably movable over an adjacent surface 33 of the carriage 23, and oppositely disposed, oblique or bevel flange portions 34, 34 thereof slidably movable over oblique or bevel surfaces 35, 35 of said carriage which are opposite said base portion 32 and said surface 33. Stated otherwise, the oppositely disposed, oblique or bevel flange portions 34, 34 are spaced from the base portion 32, as Well as from each other, and extend inwardly in oblique or bevel relation to said base portion 32, to provide oppositely disposed guideways 36, 36 of the bracket member 3| extending transversely of the carriage-23 in which opposite side edge portions 31, 31 of said carriage are snugly, but slidably, situated. The bracket member 3| is adapted to be adjusted transversely of the carriage 23 by slidable movement of said bracket member and its oppositely disposed guideways 36, 36 along the opposite side edge portions 31, 31 of said carriage.

. Said bracket member 3| supports, or includes, several, or a number of, parts of the grinding and turning machine, and mechanism is included for accomplishing sliding adjustment of the bracket m mber, with parts supported thereby, transversely of the carriage, and for causing said bracket member to be secure at any position to which set crosswise of said carriage.

As disclosed, the bracket member 3| includes an integral arm 38 disposed perpendicularly to the base portion 32 of said bracket member and situated adjacent the side portion 39 of the carriage 23 which is opposite the electric motor 22, in spaced relation to said side portion 39 and in alining relation with said carriage. An adjusting member or screw 40 is rotatably mounted and fixed against longitudinal movement, as indicated at 4|, in the arm 36, and an end portion 42 of said adjusting member or screw 40 is threadably mounted, as at 43, in said side portion 39 of the carriage. side of the portion 33 opposite the arm 38 provides clearance for longitudinal movement of the adjusting member or screw 40, as will be evident. Said adjusting member or screw 48 is arranged perpendicularly to said arm 38 and parallelly of, or in alinement with, the carriage 23, and the end portion of the adjusting member or screw 46 which is opposite the threaded end portion 42 fixedly supports a hand piece 45 through the instrumentality of which said adjusting member or screw can be rotated, thus to accomplish adjustment of the bracket member 3| transversely of the frame 26 and the carriage 23. Clearly, by turning adjustment of the member or screw 4|] in one direction, it will be caused to move inwardly of the machine, thus to cause the bracket member 3| to be adjusted inwardly, and by turning adjustment of said member or screw in opposite direction, it will be caused to move outwardly of said machine, thus to cause said bracket member to be adjusted outwardly. Obviously, the bracket member 3| will be secured in fixed relation to the carriage 23 at any location along the width of said carriage to which said bracket member may be adjusted.

Mechanism also is included for supporting and rotating a brake drum, or the like, to be ground and turned in the machine, as well as for accomplishing reciprocation of the carriage 23, together with the bracket member 3| and the A slot 44 in said carriage 23 at the iii parts supported, or included, by said bracket member, upon the frame 20.

The driven shaft 24 of the electric motor 22 is at the side of the frame 26 and the carriage 23 which is opposite the hand piec 45. A gear casing 46, constituted as a part of the frame of the machine, suitably and conveniently rotatably supports a driving shaft 41 disposed transversely of said frame and parallelly of the motor shaft 24 in spaced relation to said motor shaft. An outer end portion of the driving shaft 41 fixedly carries step pulleys 48 which are alined with step pulleys 49 fixed upon the motor shaft 24, and a belt 50 rides the pulleys 48 and 49 in customary fashion. An intermediate portion of said driving shaft 41 fixedly carries a worm 5| which meshes with a worm wheel 52.

A hollow work spindle 53 is suitably and conveniently rotatably mounted, as by Timken bearings 54, in the gear casing 46, and said hollow work spindle is suitably and conveniently fixed against endwise or longitudinal movement in said gear casing. Said worm wheel 52 is situated in the gear casing 46 and is keyed, as at 55, upon an inner reduced portion 56 of the hollow work spindle. A small gear 51, also keyed upon said hollow work spindle at is situated at the side of the worm wheel 52 opposite the Timken bearlugs and in contiguous relation With a hub 58 integral with said worm wheel. A washer 59 is disposed between said worm wheel 52 and the adjacent Timken bearing 54, and a spacing sleeve 60 is slidably situated upon said reduced portion 56 of the hollow work spindle at the side of the small gear 51 which is opposite the hub 58. Lock nuts 6| adjacent the end of the spacing sleeve 6|] opposite the small gear 51 and engaged with an external thread 62 upon the reduced portion 56 are adapted to be turned home against said spacing sleeve 60 thus to cause the worm wheel 52 and the hub thereon and the small gear 51 to be clamped against each other and between the washer 59 and the spacing sleeve GI] and said worm wheel'and small gear to be fixed against movement longitudinally of the hollow work spindle 53, as will be apparent.

The small gear 51 meshes witha second small gear 63 fixed upon a short shaft 64 suitably and conveniently rotatably mounted in the gear casing 46, and said short shaft 64 fixedly carries a worm 65 which meshes with a worm wheel 66 fixed upon a second short shaft 61 suitably and conveniently rotatably mounted in the gear casing and disposed at right angle relation to the short shaft 64. A stub shaft 68, suitably and conveniently rotatably mounted in said gear casing and disposed in parallel relation to the second short shaft 61, fixedly carries a larger gear 69 and a smaller gear 10 at its intermediate portion and a bevel gear 1| at its free end. Spaced apart smaller and larger gears, denoted 12 and 13, respectively, are splined .to the second short shaft 61 to rotate with said second short shaft and to be movable longitudinally thereon, either to be brought, respectively, into meshing relation with the larger gear 69 and the smaller gear 10, or to be removed from engagement with said larger and smaller gears 69 and 10.

A gear shifter device is for accomplishing movement of the smaller and larger gears 12 and 13 longitudinally of the second short shaft 61, selectively to cause said gear 12 to be engaged with the gear 69, or said gear 13 to be engaged with the gear 10, or both of the gears 12 and13 to be removed from engaging relation with said gears 69 and I9. Said gear shifter device includes a shifter rod 14 which is mounted, as at 15, 'in the gear casing 46 for longitudinal sliding movement; Said shifter rod 14 fixedly supports. a finger piece 18 upon its outer end to be manipu-- lated to accomplish longitudinal adjustment :of

the shifter rod, and also fixedly supports a shifter arm 11 upon itsinner end.' The shifter arm 11 includes a fork portion 18 thereof which lies between spaced apart annular elements 19, 19 slidable upon the second short shaft 61 and rigid with the smaller and larger gears 12 and 13. The construction and arrangement are such that the annular elements '19, 19 are rotatable with saidgears 1.2 and I3 and the second short shaft 61, when these are rotated, and relatively'to the shifter arm Tlfand its fork portion 18; It will. be obvious that when the shifter rod is in inserted positionras in Fig; 5, the larger gear 13 will be in mesh with the smaller gear 10, that when said shifter rod is ,in withdrawn position, the smaller gear 12 will be in mesh with the larger gear 69, and that when the shifter rod is in intermediate position, saidgears l3 and 12 will be removed from engagement with said gears and 69, respectively. Asdisclosed more clearly in said Fig. 5, the shifter rod 14 is provided with three spaced apart slots 80, and a retaining element 8| is adapted to be'resiliently pressed by a coil spring 82 into each of said slots thusv to insure that said shifter rod 74 will stably remain at each of its adjusted positions against the possibility of accidental displacement. The construction and arrangement are such that the shifter rod readily can be slid or moved to and away from any of its intended positions.

A feed member or screw 83 is suitably and conveniently rotatablymounted, as represented generally at 84, in the frame 20. Means (not shown) will of course be included to preclude 1ongitudinal movement of said feed member or screw 83. Said feed member or screw 83 is disposed longitudinally of said frame and includes an externally threaded portion 85 thereof which meshes with an-internally threaded portion 86 of the carriage 23. Also, the feed member or screw 83 extends through the gear casing- 46 and is disposed'in adjacent relation to the bevel gear I I, as well as in perpendicular relation to the'stub shaft 68 which fixedly carries said bevel gear 1|. v

The feed member or screw 83 isadapted to be rotated in either direction, thus to cause the carriage 23 to be fed forwardly or rearwardly, as may be predetermined, through the instrumen tality of the bevel gear 11, Tothis purpose, clutch means 8'! is provided. More explicitly, spaced apart, oppositelyidisposed bevel gears, indicated 88 and 89, respectively, are in surrounding, nomally free relation to the feedmember or screw 83 and in engaging relation with'opposite side portions or sides of the bevel gear H. While said feed member or screw 83 normally is freely rotatable within the bevel gears-88 and 89, said just mentioned bevel gears are suitably and conveniently fixed against movement longitudinally of the feedmember or screw to be con'-, stantly in mesh with the bevel gear H; The

clutch means 81 is slidably mounted upon, the feed member or screw 83 between the bevel gears 88 and 89 and is splined,,as at 90, to said feed member or screw. The bevel-gear 88 includes the bevel gear 88. Thedevices for accomplishsaid clutch means 8-! includes spaced'apart, external ribs 93 adapted to be alined with the longitudinally extendingribs 9| and 92. The bevel gears 88 and 89, including their ribs, are spaced from each other a distance slightly greater than thelength of the ribs 93, and said ribs 93 as shown extend substantially the full width of the clutch means 81.

Devices are included selectively for'position ing the ribs 93 of said clutch means 81 to be situated clear 'of the ribs 91 and 92, as in Fig. 6, so that both of the bevel gears 88 and 89 willbe freely rotatable upon the feed member or screw 83'.with rotation of the stub shaft 98 and the bevel gear H, for positioning said ribs 93 in engagement with the ribs 9| so that said feed. member or screw will be rotated in direction to corremember or screw will be rotated in direction to correspond, or in directionopposite that in which said feed member or screw rotates when the ribs 93 and 9! are engaged, when the stub shaft 68 25.

andbevel gear H are rotated. The feed member or screw 83 obviously will be turned with turning of the bevel gear H while the ribs 93 are I engaged with either the ribs 9| or the ribs 92. When the ribs 93 and 91 are engaged, the bevel gear 89 is clutched to the feed member or screw 83 and said feed member or screw is free to rotate withinthe bevel'gear 89, and when the ribs 93 and 92 areengaged, thebevel gear 89 is ill spaced apart, internal,longitudinally extending clutched to the feed member or screw and said feed member or screw is free to rotate within ing. sliding movement of the clutch means 8! along the feed member or screw 83 areb'est disclosed in Figs. 1, 5 and 6. A manipulating piece 94, rotatably mounted upon the gear casingz'dfi, carries a bifurcated bar 95 whichstraddles a pin 96 rigid with a wing 91 fixed to said. clutch means 81.. The wing 91 is slidably supported upon a rod 98 suitably and conveniently mounted within said gear casing and disposed parallel withthe feed member or screw 83. Said wing 9'! is adapted to be slid longitudinally of the rod v98 by rotational actuation of the manipulating piece 94, thus to cause the clutch means 7 81 to be moved longitudinally along said feed member or screw 83'. Said manipulating piece 94 may include a retaining element 99, similar to the retaining element 8!, engaged against the gear casing 49 for insuring that the clutch means 8'! stably, will remain at any adjusted position to which set.

A hand wheel I09 fixed upon a, free end of the feed member or screw 83 at a side of the gear casing 46 which is opposite the carriage 23 is for accomplishing manual rotational actuation of said feed member or screw, Evidently, when the clutch means 81 is in neutral position, as in Fig. 6, the feed member or screw can be-freely rotated in either direction through the medium The Timken bearings 54 maintain the hollow work spindle 53 in exact parallel relation with the guideways 29, 29 provided by the carriage 23, as well as in precise parallel relation with the feed member or screw 83, at a side of said guideways 29, 29 and said feed member or screw. An arbor IOI for supporting a brake drum I02 to be ground and turned includes a circular, taper part I03 of said arbor adapted to be seated in a longitudinal opening I04 through the hollow work spindle 53. More explicitly, a .part I05 of the opening I 04, defining the end portion of said opening opposite the worm wheel 52, has shape similar to that of the circular, taper part I03 of the arbor IOI to which said part I03 is adapted to be snugly fitted. A draw rod I06, including a head I01 at its outer end and an externally threaded portion I08 at its inner end portion, is for removably retaining the arbor IOI in rigid relation to the hollow work spindle 53'. As disclosed, the draw rod I05 extends longitudinally through the opening I 04, the externally threaded portion I08 of said draw rod is removably engaged with an internal thread I09 in the inner end of the arbor IOI, and the head ID! of the draw rod is engaged against the end of the reduced portion 55 of said hollow Work spindle 53 which is opposite the brake drum I02. Obviously, by turning the head I01 in one direction the arbor IOI can be made rigid with the hollow work spindle, and by turning said head I01 in opposite direction the draw rod I05 can be released from said arbor, thus to render the arbor removable from said hollow work spindle. When the head I'I of the draw rod is turned down against the reduced portion 56 of the hollow work spindle, the arbor IN and said hollow work spindle evidently are secured to each other to be constituted as a unitary entity.

As disclosed, the brake drum I02 is rigidly secured upon the end .portion of the arbor IOI which is opposite the hollow work spindle 53 by the'employment of spaced apart collars H0 and III situated at and against the opposite end portions, respectively, of a hollow hub II2 of said brake drum. The collar IIO may be adjustable along and made secure with the arbor I0'I in any suitable and convenient manner, and the collar II I may be fastened against the hollow huh I I2 by means of a nut II3 upon the outer end portion of the arbor IOI. The construction and arrangement will be such that when the nut H3 is turned home, said hollow hub I I2 will be rigidly engaged by the collars II!) and III to cause the brake drum I02 to be rigidly supported upon the arbor IOI with its part to be ground and turned in precise concentric relation to said arbor and the hollow work spindle.

It will be apparent that with rotation of the hollow work spindle 53, by the electric motor 22 and through the instrumentality of a pulley 49, the belt 50, a pulley 48, the driving shaft 41, the worm I and the worm wheel 52, there Will be rotation of the arbor IOI when rigid with said hollow work spindle and of the brake, drum I02 when rigid with said arbor.

A cylindrical tool post II4 of the machine is situated at the midwidth of the bracket member 3| and is rotatably supported by said bracket member in upstanding, perpendicular relation thereto. As shown, the lower end of the cylindrical tool post II4 includes an annular flange H5 rotatably fitted in an annular opening H6 in the base portion 32 and adapted to be slidable along the horizontal surface 33. The lower portion of said cylindrical tool post is snugly, but rotatably, fitted, at 1, in said base portion 32, and a collar II8 fixed to the tool post and engaged against the upper surface of the bracket member 3| cooperates with the annular flange I I5 to fix said tool post against longitudinal movement.

Said bracket member 3| includes an annular reduced portion H9 at its outer or upper side in surrounding, concentric relation to the cylindrical tool post, and a swivel plate I20 is rotatably mounted upon said annular reduced portion II9 to rest upon and be slidable over the outer or upper surface of the bracket member. The swivel plate I20 includes an arcuate slot I2I in spaced relation to the annular reduced portion H9 and disposed transversely of said swivel plate and of the bracket member 3|, and a screw bolt I22 passing through said arcuate slot I2I and entering said bracket member is for releasably fixing the swivel plate at any position to which slidably adjusted upon the bracket member about the reduced portion II9 as an axis.

A grinding tool holder of the machine is indicated at I23, and a turning tool holder is denoted at I24.

The turning tool holder I24 is rotatably mounted upon the cylindrical tool post I I4 in contiguous relation to the swivel plate I20. More explicitly, said turning tool holder includes a body portion thereof having its base contiguous with and slidable over said swivel plate, and an upstanding, hollow tubular portion I25 thereof, at a side of said body portion, snugly and rotatably situated upon an intermediate portion of the cylindrical tool post in adjacent relation to, or contiguous relation with, the collar I I8.

The grinding tool holder I23,.also is rotatably mounted, upon said cylindrical tool post I I4, and is.adapted to be in contiguous relation with the swivel plate I20, or in spaced relation to said swivel plate. More explicitly, said grinding tool holder includes a body portion thereof the base of which is adapted to be in contiguous relation with the swivel plate I20, as in Figs. 2 and 7, or in spaced relation to said swivel plate, as in Fig. 9, and an upstanding hollow tubular portion I26 thereof, at a side of an upper part of said body portion, snugly and rotatably and longitudinally slidably situated upon said cylindrical tool post I I4 at location above the upstanding hollow tubular portion I25.

Said turning tool holder I24 suitably and conveniently supports, as at I21, a turning tool I28 including a cutter I29 adapted to be engaged with the internal surface of a brake drum to be turned in the manner as best disclosed in Fig. 14. When said cutter I29 is in operative position the turning tool holder I24 and the grinding tool holder I23 are relatively situated as in Fig. 9. That is to say, said grinding tool holder is elevated to a position where it is in spaced relation to the swivel plate I20 at elevation above and clear of said turning tool holder when the turning tool is to be put to work.

Said grinding tool holder I23 suitably and conveniently supports, as at I30, a supporting shaft I3I which rigidly carries a grinding tool I32 adapted to be engaged with the internal surface of a brake drum to be ground in the manner as best disclosed in Fig. 1. When said grinding tool I32 is in operative position the grinding tool holder and the turning tool holder are relatively situated as in Figs. 1, 2 and 7. That is to say, said grinding tool holder is situated in contiguous relation with theswivel plate I20 at the elevation of said turning tool holder when the side of said tool post opposite said hand piece,

with the cutter of said turning tool extending in direction toward said brakedrum. In said Fig. 9, numeral- I33 represents a spring-pressed index pin carried by the turning tool holder I24. disposed in an index opening I34 in the swivel plate I 20, and I35 denotes an index opening in said swivel plate situated at 180 from the index opening I34. In practice, aid turning tool holder is. rotated upon the swivel plate until the index pin- I33 enters the index opening I34 when it is the intention to accomplish a turning operation in the machine, and is rotated until said index pin enters the opening I35 when it is the intention to perform a grinding operation. The turning tool holder I24 is in. Fig. Z'spaced at 180 from its position as in Fig. 9.

Also it will be seen that the grinding tool holder I23 is located in Figs. 1 and 2 at the side of the tool post II4 opposite the hand piece 45 with the grinding tool I32 upon the supporting shaft I3I disposed'in grinding relation to the brake;

drum to be operated upon. In said Figs. 1 and 2,

the grinding and turning tool holders are in proper grinding relation to said brake drum,

That is to say, the turning tool holder when set at itsv inoperative position constitutes means in the machine for causing the grinding tool holder to be situated at proper grinding position of the grinding tool.

The disclosure includes mechanism for raising and. lowering, or longitudinally moving, the grinding tool holder I33 along the cylindrical tool post H4 and for insuring that said grinding tool holder will stably remain at any position to which-moved; A rack I33 extends longitudinally of said tool post, and an operating spindle I3] is rotatably mounted, as at I39, in. the grinding tool holder." Said operating spindle includes a gear I39 in mesh the rack I35 and an operatin crank I40. Said grinding tool. hold'er'l 23 is fixed, as at I141, against rotational: movement I upon the tool post 4- thus to insure the set relaing, tool holder and engaged withsaid. tool post is for precluding movement ofsaid grinding tool holder along the tool post save when such movement. is. intentional. e The disclosure also includes devices for fastenupper end'of said part-cylindrical spacer to cause the lower end. of the spacer to be tight against said tubular portion I26 thus to cause the grinding and turning tool holders and the swivel plate I to be'fixed upon said bracket member 3|. In Fig. 9 said part-cylindrical spacer I43 islocated betweenthe base of the grinding tool holder and the tubular portion I of the turning toolholder, and the clamping nut I44 is turned home against the upper end of the tubular portion l26'of said grinding tool holder to cause said tool holder and the swivel plate to be fixed upon the bracket member.

I The supporting shaft I3I and the grinding tool I32 are adapted to be rotated through the instrumentality of a second electric motor, represented at I45, adjustably mounted upon the grinding tool holder I23. To this end, a belt I rides a pulley I4'I fixed upon the shaft of said electric motor I45 and also rides a pulley I49 fixed upon said supporting shaft I3I. The electric motor I 45 is fixed upon a bracket I49 pivoted at I upon thegrinding tool holder I23,

and an adjusting screw I5! threaded in said -grinding tool holder has its end opposite the head'of said adjusting screw engaged against a portion of the bracket I49 spaced from its pivotal support. Evidently, by turning of the adjusting ing each of the grinding toolholder and the turning, tool holder: when in operative position rigidly against the swivel plate I20. and: the bracket member 3L. I43 designates a part-cylindricala spacer adapted toberemovably situated upon the tool post Ii -'4,

and I441 denotes av clamping-nut upon the outer or free end. of said tool. post. In. Figs. 2" and 7 the part-cylindrical spacer I43 is located between the-clamping nut I44 and the tubular portion I26 of the. grinding tool holder I23, and said clamping nut is turned home against the- Of said devices, numeralv screw I5I said bracket I49 can be moved to situate the electric motor I45 and its shaft with pul ley I41 farther irom or closer to thepulley I48 thus to adjust the tension of the belt I45.

The electric motors 22 and I45 are adapted to be energized by current from a source (not shown) of electrical energy, and a circuit for said electrical motors is adapted to include an on-and-ofi switch I59 having" an actuating lever I52. Said actuating lever is adapted to be manually moved to the on position of said switch I59, and mechanism for controlling operation of the actuating lever, thus to control operation of the electric motors 2 2: and I45, includes latch means adapted to normally maintain said actuating lever in the closedcondition of said switch I59 and cam means for causing said latch means to release the actuating lever I52 for movement to the open condition of the switch upon movement of the carriage 23-to both its forward and rearward limit positions.

The on-and-off switch I59 having the actuating lever I52 is mounted upon the frame 29. An operating rod I53 for said actuating lever I5 2 is slidably mounted in spaced apart bearings I54 and I55 upon said frame and is disposed in the carriage 23. A'bifurcated element I 59 rigid with the operating rod I53 straddles said actuating lever I52, and a 'coil compression spring I51 upon said operating rod and between the bearing I55 and a head I58 on the rod has potential to urge the operating rod to position said actuating lever in the off condition of said switch I59.

A latch element I99 is slidably mounted in a cup-shape member IfiI' rigid with the frame 2|] and is disposed transversely of the operating rod I53. A portion of the latch element at the closed side of the cup-shape member is notched, as at ton I63, and a coil compression spring I54 upon the latch element and between the base of the cup-shape member and the button I63 normallymaintains said button at elevation somewhat above the open end of said cup-shape member.

Spaced apart cams I65 and I66 are adjustably supported, as at I61, upon a rod I68 fixed to the carriage 23 and disposed parallelly of the operating rod I53. Working surfaces I69 and I10 of said cams I65 and I66, respectively, are in facing relation to each other.

The working surface I 69 is adapted to cause the button I63 to be depressed against the resilient action of the coil compression spring I64 when the carriage 23 reaches the limit of its rearward movement, and the working surface I10 is adapted to cause said button I63 to be depressed against the resilient action of said coil compression spring I64 when said carriage reaches the limit of its forward movement. The construction and arrangement are such that when the button I63 is in elevated position, as in Fig. 10, the notched part of the latch element I60 lies in a transverse slot I1I of the operating rod I53 so that the notch I 62 is out of alinement with the operating rod, as in Fig. 11, and whensaid button I 63 is depressed by either the working surface I69 or the working. surface I10 said notch I62 becomes alined with said operating rod I53, as in Fig. 12. Upon alinement of the notch I62 with the operating rod, the coil compression spring I51 will of course act to move said operating rod longitudinally thus to remove the transverse slot I1I from the location of the latch element I60 and its notch I62.

In practice, as the carriage 23 comes to rest at either of its limit positions the latch element I60 will become depressed by one of the cam working surfaces I69 or I10, and the operating rod I53 will be longitudinally slid by the coil compression spring I51 so that said operating rod will cause said latch element to be held depressed against the action of the coil compression spring I64 while the machine is at rest. The longitudinal sliding movement of said operating rod caused by the coil compression spring I51 will of course move the actuating lever I52 to the off condition of the switch I59. When the carriage reaches either of its limit positions, the clutch means 81 will be manually operated to cause the direction of feed of the carriage to be reversed. Then, upon manual actuation of the operating rod I53 inwardly against the resilient action of the coil compression spring I51 to cause the actuating lever I52 to be moved to the on condition of the switch I59, the transverse slot I1I will be alined with the latch element I 60 and said latch element obviously will be released from its switch-off position as in Fig. 12 to become situated at its switch-on position as in Figs. 10 and 11 with the commencement of feeding of the carriage and movement of the cam working surface, I 69 or I10, which was in engagement with the button I63 in direction away from said button. Attention is called to the fact that the button I63 will be released by either of the cam working surfaces I69 or I10 in response to quite slight feeding movement of the carriage 23, so that the latch means will cause the actuating lever I52 to be fastened in the on condition of the on-and-oif switch I59 substantially immediately after the electric motor 22 is set in operation. Of course, either of the cam working surfaces I69 or I10 can be removed from the button- I63 by manual rotation of the hand wheel I00. The switch I59 can be placed in the circuit of only one of the electric motors 22 or I45 in an instance where this is desirable.

It will be apparent that brake drums, or the like, can be smoothly and accurately finished and trued by employment of grinding and turning entities of the nature as hereinbefore described. Also it will be apparent that different types of grinding and turning tools can be employed in the machine. A brake drum, or the like, being operated upon can be rotated at any of several difierent speeds through the medium of the step pulleys 43 and 49. Additionally, there is provision in the machine for a faster and a slower forward power feed and a faster and a slower rearward power feed of the carriage 23. With increase of the speed of rotation of a brake drum being ground and turned there will be increase of the rate of feed of said carriage 23, and vice versa. As before stated, the hand wheel I60 constitutes means for manually accomplishing forward and rearward feed of the carriag 23.

Attention is called to the fact that the grinding tool I32 and the turning tool I28 with cutter I 29 can be accurately angularly adjusted to cause a precise operation to be performed upon a brake drum, or the like, supported in the machine simply by rotatably adjusting the swivel plate I20 upon the annular reduced portion H6. Clearly, adjustment of said swivel plate will .cause the grinding and turning tools to be angularly adjusted relatively to the work to be done.

In Figs. 15 and 16 there is disclosed a brake drum support of modified construction adapted to be employed in the machine. Parts in said Figs. 15 and 16 similar to parts previously described bear the same reference numerals.

The gear casing 46 rotatably supports the hollow work spindle 53, as by Timken bearings 54, as before set forth. The worm wheel 52 and the small gear 51 are keyed to said hollow work spindle and are fixed against movement longitudinally of the hollow work spindle in the manner as hereinbefore stated.

An arbor I12 integral with a brake drum I13 to be ground and turned extends through a longitudinal opening I14 in the hollow work spindle 53. A compound clamp I15 includes a part I16 thereof releasably grasped upon the end portion of said hollow work spindle adjacent the brake drum and opposite the worm wheel 52 and a part I11 thereof releasably grasped upon an enlarged portion I18 of the arbor I12 adjacent said brake drum. The compound clamp I15 is adapted to support the arbor I12 and the part of the brake drum I13 to be operated upon in exact concentric relation with the hollow work spindle 53. A hollow fitting I19 includes an annular portion I30 thereof removably fitted in the free end poition of the reduced portion 56 of the hollow Work spindle 53, a flange portion I8I thereof adapted to be engaged against the free end of said reduced portion 56, and an annular externally threaded portion I82 thereof at the outer side of said flange portion I8I. The end portion of the arbor I12 opposite the brake drum I13 passes snugly through the hollow fitting I 19. A nut I83 includes an internal thread adjustably engaging the external thread upon the annular portion. I82, and a split washer I84 is adapted to be removably situatedjn an annular groove I85 in the free end portion of the arbor I12, between a head I86 of said arbor and the adjacent surface of the nut I 83. Evidently, by turning the nut I83 outwardly on the annular externally threaded portion I82 and against the split washer I84, the arbor I12 can be drawn in direction to bring an internal surface of the compound clamp I15 into pressing engagement withthe adjacent end of the hollow work spindle 53 to make said arbor rigid with said hollow work spindle, and byturning said nut ,l83 inwardly on said annular portion I82 and away from said split washer, the split washer can be released for removal from the annular groove I85, thus to render the arbor l'l2 removable from the hollow work spindle. Whenthe nut I83 is in pressing engagement with the split washer I84, the arbor I12 and said hollow work spindle are secured to each other to be constituted as a unitary structure.

What is claimed is:

1. In a grinding and turning machine, a frame, a, support for an article to be ground and turned rotatably mounted upon said frame, a. carriage reciprocable upon said frame, means for rotating said support and for reciprocating said carriage in directions toward and away from said article, a bracket member upon said carriage, means for adjusting said bracket I member transversely of t e direction of reciprocation of said carriage, a tool post, rotatable in said bracket member and slidably supported by said carriage, a first tool holder having a lower body portion thereof adapted to be supported by said bracket member and an.

upper hollow tubular portion thereof at a side of said body portion slidably mounted on said tool post, a working tool carried by said first tool holder, a second tool holder having a lower body portion thereof supported by said bracket member and an upper hollow tubular portion thereof at a side of said body portion rotatably mounted on said tool post, a working tool carried by said second tool holder, complemental means for adjusting one of said tool holders longitudinally of said tool post, means for rotating one of said working tools, a part-circular spacer adapted to be removably situated upon said tool post selectively between and above said mentioned hollow tubular portions, and a nut upon said tool post of said first and saidsecond tool holders against atthe side of said hollow tubular portions oppo-' site said bracket member for clamping said partcircular spacer and the hollow tubular portions portion slidably mounted on said tool post, a

working tool carried by said first tool holder, a

' second toolholder having a lower body portion thereof supported by said supporting member and an upper hollow tubular portion thereof at a. side of said body portion rotatably mounted on said tool post, a working tool carried by said second tool holder, complemental means f or adjusting one of said tool holders longitudinally of said tool post, means for rotating one of said working tools,

a part-circular spacer adapted to be removably situated upon said tool post selectively between and above said mentioned hollow tubular portions, and a nut upon said tool post at the side of said hollow tubular portions opposite said supporting member for clamping said part-circular spacer and the hollow tubular portions of said first and said second tool holders against said supporting member.

' OLOV J. E. OLSSON. 

